The structures that produce male gametes (sperm) in humans are the testes.

Here's a breakdown:

* Testes: These are the primary male reproductive organs. They are located in the scrotum, a pouch of skin that hangs outside the body.

* Seminiferous tubules: Within the testes, tiny, coiled tubes called seminiferous tubules are where sperm production (spermatogenesis) occurs.

* Leydig cells: These cells are found in the spaces between the seminiferous tubules and produce testosterone, the primary male sex hormone.

So, while the testes are the overall producers of sperm, it's the seminiferous tubules within the testes that are the specific site of sperm production.